A strong correlation between improved sanitation and significant increase in the prevalence of autoimmune and autoinflammatory syndromes has been demonstrated in western countries. Moreover, a correlation between the presence of parasitic worms (helminths) in certain geographic areas and protection from atopic, autoimmune, and autoinflammatory diseases was reported. These studies led to the “hygiene hypothesis”, postulating that the recent increase in autoimmune disease incidences in the west reflects an absence of appropriate priming of the immune response by infectious agents, including parasitic worms, during childhood.
During the last decades many studies reported that infection with parasitic helminthes, or systemic treatment with helminths extracts, can reduce inflammation associated with autoimmune diseases, such as multiple sclerosis (MS), rheumatoid arthritis (RA), type I diabetes mellitus (T1DM), and inflammatory bowel disease (IBD).
Although such studies were successful, using potential pathogens as therapeutic agents has raised ethic and safety issues. Therefore, considerable effort has been spent in identifying and characterizing the parasite-derived molecules responsible for their immunomodulation.
The currently most-well defined nematode-derived immunomodulatory molecule is ES-62. ES-62 is a tetrameric glycoprotein (62 kDa subunits) that has phosphorylcholine (PC)-moieties attached via an N-type glycan.
It has been proposed that the immunomodulatory activity of ES-62 is attributed to the presence of the PC moieties. Further support for the PC immunomodulatory activity was found in other parasitic nematodes like Ascaris suum that express only the PC-immunomodulatory moiety.
U.S. Pat. No. 5,455,032 discloses compositions useful for inducing immunoprotection against infections by pathogenic organisms containing phosphocholine antigens, including Streptococcus pneumoniae and other microorganisms that have a phosphocholine antigen component on their membranes or capsids. Further disclosed are vaccines and methods for inducing immunoprotection against infection by these pathogenic organisms.
U.S. Pat. No. 7,067,480 discloses the use of a phosphorylcholine-containing glycoprotein, particularly ES-62, in the treatment or prophylaxis of autoimmune diseases associated with abnormal inflammation such as rheumatoid arthritis.
U.S. Pat. No. 8,012,483 discloses a method for identifying subjects at risk of developing ischemic cardiovascular diseases by determining the presence of antibodies, particularly IgM antibodies, toward phosphorylcholine and further discloses pharmaceutical compositions comprising a phosphorylcholine conjugate, or an antibody with specificity to a phosphorylcholine conjugate for active or passive immunogens in the treatment or prevention of atherosclerosis.
U.S. Patent Application, Publication No. 2010/0303721, discloses a method of treating an excessive immune response including an aberrant/enhanced Th1 response with a helminthic parasite preparation. The autoimmune diseases includes Crohn's disease and ulcerative colitis, rheumatoid arthritis, type 1 diabetes mellitus, lupus erythematosus, sarcoidosis, multiple sclerosis, autoimmune thyroiditis, allergic rhinitis, colon polyps/colon cancer and asthma.
There remains a need to develop small molecules as safe and stable immunogens, with minimal adverse side effects, for treating autoimmune diseases, particularly disease associated with abnormal inflammation.